Don Anderson, Holding Back Red Tide

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June 29, 2007

The ocean is teeming with plants, and most of them are good for
marine animals and the planet as a whole. But as with anything in life, it is
possible to have too much of a good thing. Biologist Don Anderson studies an insidious
and sometimes fatal form of overindulgence: harmful algal blooms.

Algae are microscopic, single-celled plants that live in the
oceans and many other bodies of water. Most species of algae (a form of
phytoplankton) are plentiful, harmless, and incredibly valuable as the chief
energy producers at the base of the marine food web, without which higher life
on this planet would not exist.

Among the thousands of species of algae and phytoplankton in
the sea, a few dozen produce toxins and pose a formidable natural hazard commonly
called “red tides.” Sometimes they
reproduce prolifically, discolor the water, and foul beaches with foam from
their prodigious booms. Other times these harmful algae are dilute and
invisible, nearly inconspicuous if not for the destruction they cause--a bloom
of harmful algae can completely and permanently alter the structure of a food
chain, causing massive die-offs of shellfish, marine mammals, fish, seabirds,
and other animals that consume them. They can also sicken, disable, or kill
humans who eat fish or shellfish that have ingested the toxic algae.

Don Anderson and his research colleagues are keenly
interested in a toxic dinoflagellate known as Alexandrium, a genus
responsible for poisonous red tides in many countries throughout the world. In
2005 alone, this harmful alga caused more than $50 million in lost revenues for
New England’s seafood industry, as clam and shellfish beds from Narragansett
Bay the Bay of Fundy had to be closed off to fishermen.

In the years since that dreadful bloom, Anderson and his
team have been creating a regional observation and modeling program focused on
the Gulf of Maine
and its adjacent New England shelf
waters. The project uses a combination
of large-scale survey cruises on research vessels, autonomous underwater
vehicles, moored instruments and traps, drifting instruments, satellite
imagery, and numerical models to understand the dynamics, transport pathways,
and toxicity of Alexandrium. They
share this information with coastal managers, regulators, and fishing
interestsand, most of all, the seafood consumer--to protect nearshore and
offshore shellfish resources that can be threatened by paralytic shellfish
poisoning. The researchers are even working to develop automated sampling instruments
that could be left in the ocean to monitor the development of harmful algal
blooms before they endanger the coast. Ultimately, Anderson and colleagues
would like to be able to forecast algal bloom seasons in order to mitigate the
impact on our coastal resources.

Donald Anderson, Senior Scientist and Director of the Cooperative Institute of the North Atlantic Region (CINAR) . (Photo by Pat Tester, NOAA)

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